Neutronic reactor



Dec. 25, 1962 E. P. wlGNER 3,079,529

NEUTRONIC REACTOR Filed March l, 1946 Y aiaszs Patented Dec. 25, 1962 3,070,529 NEUTRONIC REACTQR Eugene P. Wigner, Princeton, NJ., assignor to the United States of America as represented by the United States Atomic Energy Commission Filed Mar. 1, 1946, Ser. No. 651,282

Claim. (Cl. 204-1932) This invention relates to atomic power plants, and a novel method and means for nuclear fission chain reaction to produce steam for power or other purposes.

In neutronic reactors a thermal neutron issionable isotope such as Um, U235, or 94239 or mixtures thereof is evolved by the fission. The term thermally ssionable as herein used means, as is common in the art, iissionable by thermal neutrons. In general such reactors comprise slowing material which slows the neutrons to thermal Such a slowing material is termed a neutron moderator. Carbon, D20 (heavy water), and ordinary water are typical moderators suitable for such use. Heat is evolved during the reaction which is removed by passage of a coolant through the ber 19, 1944, now Patent No. 2,708,656.

In neutronic reactors, the ratio produced in one generation by the fissions to the original in a system of of any size disposed in a may be lost to the chain (4) by leakage out of the system through the periphery thereof.

This which may be employed with any of the various combinations of materials which are already Well known.

A general object of the invention is to design a system such as above duction ratio of the composition is decreased by the According to the elevation.

Describing the comprises a vessel permeable material stainless steel, said invention in detail, the novel device 4 of any suitable waterproof neutron such as, for example, aluminum or `D2O-l-DF uranyl bicarbonate, UO2(DCO3) 2, dissolved '02804, dissolved in a mixture of D2O+D2SO4g uranyl itrate, UO2(NO3),2, dissolved in a mixture of D20;

lutonium sulfate,"Pu(SO4)2,'dissolved in a mixture of )zO-l-D2SO4; or plutonium peroxide dissolvedy in a mix'- ure ODZO-i-Na'ZCOa. -In the uranium solutions, the iranium may have a natural or an enriched isotopic :ontentf of thermally fission'able' Um. The reactive comlosition'is supplied to thetrays by a headerV 12 having t pluarlity of outlets-14 communicating with respective rays.

Asaresult of the nuclear fission chain reaction'within the reactionwzone defined by the trays6,`the'liquid content of the reactive composition boils, and is vaporized to form steam, which` is conveyed from the vess'e1`4 by an outlet pipe-16 adapted to communicate with a conventionalsteam.operated power device. If desired, the pipe 16 may be provided with any, suitable filter (not shown) for eliminating'radioactive ssion productsV of the chain reaction, which products may become entrained in the' steam passing from theVvessel 4. As the liquid is vaporizedifromthe trays 6, it is replenished by the header' 12 through conduitsV 14 to maintain a substantially constantvliquid level within the trays. rOverliow of the reactive composition from'the trayspasses through perforations 18 inthe bottom of the vessel 4 .and is conveyed from vthe system asY is hereinafterdescribed.

`.The bottomof the tube 8,.-s provided witha nut 20 threaded into the tube to aord av` therefor, and rthe head ofthe. nut, rests onthe conical oor 22 of ahollowneutron reflector 24 containing the vessel 4, said reflector 24 being formed of any suitable scattering or. moderating material, such as graphiteor beryllium adapted to reflectneutrons escaping from the vessel '4back finto Vthe same, thereby .increasing the neutronY reproduction ratio of l-thefreac'tive composition therein. Y Y

One or more outlet or drain pipes 2, communicate with the interior of the reector 24at the baser of the conical oor 22 ,to draink ove'row composition draining fromthe vessel.4. In this connection, itwill be understoodtthatV it is necessary from time. to time to wash all thefssionable .material .from -the .trays 6 inr order kto renew the. iissionable materialandprocess the lbombarded mater-ialto recover .fission productsnof .the reaction. If desiredfthe .iloor22 may bevprovided -with a suitable liner tofpreventicontamination Vofthe.reflector 241by the overflow reactive compositionqfromthe trays 6.

The nuclear` lission chain reaction isxcontrolledgbyxa rod 28 of a neutron absorbent: material, suchxas cadmium, said rod being reciprocablewithin theztube 81 as by .a rack and pinion mechanism' 29. Thertop `ofi the .hollow Huid-tight closure be sealed by a biologicalrshield (not shown) .similarV to the before-mentioned shield 30.

Obviously the illustrated embodiment of the invention is diagrammatic, and many modifications thereof will vbe readily apparent to those skilled in the art without departing from the `spiritV of the invention or the scope of the appended claim.

What is claimed is:

A neutronic reactor'comprising a plurality of hori- Yzontal trays containing, in an amount suicient to sustain a chain reaction, a solution of ar material iissionable by neutrons of thermal energy in a liquid moderator, each tray containing a portion of said solution, a vertical tube upon which the trays are sleeved in spaced relation, a 'neutron'absorbingro'd reciprocable within'the tube, a gas-tight 'chamber enclosingy saidV trays,. an outlet pipe communicating with;the'top off said chamber to conduct vaporized moderator therefrom, andv conduits communicatingwithY each' of said trays' to replace moderator lostA therefroml by evaporation.

References- Cited inthe iile 4of thisv patent .UNITEDQSTATES PTENTS 542,626 Cardozo., Juiy;16,"1s95 1909,028 4VSchalitz .f. ?Ian. 5,1909 `1,324,417 Thunholml.. .Dec. 9,1919 2,708,656 Fermi=et1al ;Mayi17, 1955 i FOREIGN. PATENTS 114,150 Australiav May 2, 1940 1 114,151 vvAustralia May'3, 1940 233,011 Switzerland June 30, k17944 OTHER REFERENCES RevewsbflModern Physics, vol 17, No. 4, October 1945, pages 3.67,v 447, 460 (part of Smythzarticle).

fMDDC-8V93 U..S. Atomic Energy Commission V(F. Daniels),..date 1declassitied April`71947, .pages 3, 5,110, 11.

'.Her Majestys StationeryOice, 1946f1951.publishcd 19524 Harwell, Theritish Atomic Energy Research Establishment, London, pages .B4-42.

vA.E.C.D. 3063 Scptember 4, l 44, pp."ll4, 417, 20 (U.S. Atomic Energy Comm.) 

